Improvement in drilling apparatus



UNITED STATES PATENT OFFICE.

JOHN MCKAY, OF NEWOASTLE-ON-TYNE, ENGLAND.

IMPROVEMENT IN DRlLLING APPARATUS.

Specication forming part of Letters Patent No. 163,503, dated May 18,1875 application filed February 23, 1875.

To all whom it may concern:

Be it known that I, J oHN-MCKAY, of Newcastle-on-Tyne, Northumberlandcounty, En gland, have invented certain Improvements in Head-Stocks forDrilling-Machines, of which the following is a specication:

The object of my invention is to so construct the head-stock ot' adrilling or boring machine as to bore or drill holes with great accuracyand speed; and this object I attain in the manner which I will nowproceed to describe, reference being had to the accompanying drawing, inwhich- Figure l is a side view of my improved head-stock; Fig. 2, afront view; Fig. 3, a sectional View; Fig. 4, a sectional plan; Fig. 5,an inverted plan view 5 and Figs. 6, 7, 8, and 9, views illustrating amodification of my invention.

In the center of the head-stock D is a longitudinal chamber, Gr, inwhich the ram F of the pivot-pin E is arranged to slide. At equaldistances from the center of this chamber, and in a parallel line, arebored two chambers, O G, in each of which is arranged to slide a ram, B,carrying at its lower end a cutter, A, Fig. 3. These chambers O G Ocommunicate with each other at the top, and are filled through theaperture c with water or other suitable liquid. Each of these rams B Band F are provided with packing a, so as to present a water-tight joint.A pin, H, projects horizontally through the ram F, and through slots .nin the side of the head-stock, so as to prevent the said ram fromturning in the chamber G.

The same object may be attained by making the chamber G and ram H ofsquare or angular section.

Through each of the rams B, and through slots yin each side of thehead-stock, projects a pin, I, these pins being connected together bythe bar l. Y

Springs L, connected at one end to projections b on the head-stock, andat the other to the bars K, control the action of the rams B.

The plate, tube,'or other article to be drilled is so arranged, inrespect tothe head-stock, that the pivot-pin E will rest on the plate inthe center of the intended hole to be bored. The head-stock is thenrotated and a downward pressure applied, so that the ram F will recedeinto the chamber Gr, forcing the liquid into each ofthe chambers C, whenthe cutters A will descend onto the plate, and, rotating round thecenter point E, will accurately bore the required hole.

When the pressure is removed from the head-stock, the springs L willdraw back the cutters, which, through the medium of the liquid in thecommunicating chambers, Will return the ram F and pivot-pin E back againto their'normal positions, Fig. 3.

A modiiication of my invention is shown in Figs. 6, 7,8, and 9, in whichthe head-stock has one central chamber, G', in which is arranged toslide the ram B', carrying the cutters A A', which are arranged at equaldistances from the center-pin E', round which they rotate. Through thecenter of this ram B' extends a chamber, G', in the upper enlargedportion of which slides the ram F', the lower portion of this ramterminating in the pivot-pin E'. Into each side ot this ram B' isscrewed a pin, I-I', these pins extending through slots z, and beingunder the control of the springs L'. Packing-rings a' secure water-tightjoints for the rams B' and F'.

When pressure is applied to the head-stock D', the pin E', coming incontact with the article to be bored, will recede with its ram F' intothe chamber Gr', when the displacement of the liquid in the chamberswill consequently force the ram B' and cutters A' down onto the materialto be operated on with the result described above.

I claim as my invention- 1. The combination, in a head-stock fordrilling and boring machines, of the centerpin E, adapted to a chamber,G, with the cut, ter-rams B, adapted to chambers G, the said chamberscommunicating with each other, and containing liquid, as and for thepurpose set forth.

2. The combination of the center-pin E and its ram F, and the rams B,carrying the cutters A, and under the control of springs L, with thecommunicating chambers C G C, containing liquid, as specified.

. In witness whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JOHN MOKAY.

Witnesses:

WM. DAGGETT, Ncwcastle-npon-Tyne, Notary Public. CHARLES BLAGBURN,Newcastle-iqon-Tyno, Consulting Engineer.

